Performance and electron transport properties of TiO₂nanocomposite dye-sensitized solar cells

Abstract

TiO(2) nanowire (NW)/nanoparticle (NP) composite films have been fabricated by hybridizing various ratios of hydrothermal anatase NWs and TiO(2) NPs for use in dye-sensitized solar cells (DSSCs). Scanning electron microscopy (SEM) images reveal that uniform NW/NP composite films were formed on fluorine-doped tin oxide (FTO) substrates by the dip-coating method. The NWs are randomly but neither vertically nor horizontally oriented within the composite film. The TiO(2) NP DSSC possesses superior performance to those of the NW/NP composite and the pure NW cells, and the efficiency of the NW/NP composite DSSC increases on increasing the NP/NW ratio in the composite anode. All types of DSSC possess the same dependence of performance on the anode thickness that the efficiency increases with the anode thickness to a maximum value, then it decreases when the anode is thickened further. Electrochemical impedance spectroscopy analyses reveal that the NP DSSCs possess larger effective electron diffusion coefficients (D(eff)) in the photoanodes and smaller diffusion resistances of I(3)(-) in electrolytes compared to those in the NW/NP and the NW DSSCs. D(eff) decreases when NWs are added into the photoanode. These results suggest that the vertical feature of the NWs within the anodes is crucial for achieving a high electron transport rate in the anode.

An Overview Of Nanonet Based Dye-Sensitized Solar Cell (DSSC) In Solar Cloth

“…Even though the electron diffusion through the metal oxide layer faster than the electron recombination with oxidized dyes on the TiO 2 surface or I−3 in the electrolyte for achieving an efficient DSSC, trapping or detrapping events, (Eqs. (5) and (6)) will be occur consequence slow electron transport rate in this layer [10]. This event makes the performance of DSSC decreased and inefficiently.…”

“…The DSSC principle is applied from the photosynthesis process and diffusion is a major mechanism for electron to travel through the oxide layer [10]. The working principle of DSSC involved several steps as shown in Fig.…”

“…Recently, some researchers have been explored the transporting of electron. In the DSSC, diffusion is the major mechanism for electron to travel through [6,10]. Today, some researchers use TiO2 as metal oxide semiconductor layer because of the material is cheap, chemically stable and non-toxic material, biocompatible, and have higher refractive index [8,15,16,22].…”

Enhancing Electron Collection Efficiency and Effective Diffusion Length in Dye‐Sensitized Solar Cells

“…It reveals that the electron transport rates of the four cells measured by IMPS are in order of horizontal TiO 2 -NW < TiO 2 -NP < ZnO-NW array/NP composite < vertical ZnO-NW array, which is consistent with that of D eff in the four anodes obtained from EIS measurements. [6,11] Although ZnO NWs and TiO 2 NWs both possess single crystalline www.chemphyschem.org structure, the vertical ZnO-NW array anode and the horizontal TiO 2 -NW anode possess the shortest and the largest electron transit times among the four types of photoanodes, respectively. The electron transit times in the horizontal TiO 2 -NW anode are even one order of magnitude larger than those in TiO 2 -NP one.…”

Characteristics of Boron Decorated TiO2Nanoparticles for Dye-Sensitized Solar Cell Photoanode

“…Recently, many efforts have focused on creating novel structures to enhance PV performance, and the working mechanism of the DSSC system has been gradually realized. Particularly, TiO 2 photoanodes, including core-shell nanowire structures [10,11], surface treatments and synergistic, mixed-phase TiO 2 , and hybrid structures [12][13][14], which provide a feasible synthesis and a simple method, have been widely utilized to enhance DSSC efficiency. On the other hand, decorated TiO 2 photoanode technologies have emerged to improve DSSC performance by means of metal/nonmetal doping [15][16][17].…”